Government discharge regulations have long recognized the dangers of discharging wastewater with significant concentrations of phosphorus and nitrogen. Most states have stringent requirements mandating that phosphorus and nitrogen concentrations in effluents discharged from wastewater treatment plants be extremely low. These regulations, of course, apply to municipal, county and regional wastewater treatment plants. However, the dangers associated with nitrogen and phosphorus concentrations in wastewater are not confined to conventional wastewater treatment processes conducted by wastewater treatment plants. Stormwater runoff contains a significant amount of phosphorus, nitrogen, and other pollutants. Many states and government entities are beginning to direct attention to reducing the phosphorus and nitrogen concentrations in stormwater runoff.
In some locations, local governments have issued guidelines requiring that phosphorus and nitrogen be removed from certain stormwater runoff, and have required the installation of structures in an effort to reduce nitrogen and phosphorus pollutants from stormwater runoff. However, for the most part the types of structures and systems being utilized to deal with phosphorus and nitrogen in stormwater runoff have been inefficient and expensive to build and maintain. Many such systems and processes only remove approximately 25% to 50% of the nitrogen and phosphorus in the stormwater runoff.
There is a need for an efficient filtering system that is relatively inexpensive, easy to maintain, and which will remove substantial concentrations of phosphorus, nitrogen, and other pollutants from stormwater runoff and other types of wastewater, such as domestic wastewater.